Lubricant of high film strength



July 26, 1938. w. JfMARsH LUBRIcAfiT OF HIGH FILM vSTRENGTH File d March16, 1936 uqtvow INVENTOR.

ATTORNEY Patented July 26, 1938 LUBRICANT OF HIGH FILM STRENGTH WilliamJ. Marsh, Niagara Falls, N. Y., assignor to Hooker ElectrochemicalCompany, New York, N. Y., a corporation of New York Application Marchis, 1936, Serial No. 69,011

' 10 Claims.

It is now well known that the halogens, and more particularly chlorine,when introduced in very small quantities into lubricants, have theproperty of greatly increasing their film strength,

i. e. the load carrying capacity of the lubricant. It is customary tointroduce the chlorine by first combining it chemically with a suitablematerial, thus producing what is known as a flimstrengthening agent.This agent is then added in minor proportion to the lubricating oil. Forthis purpose it is necessary to use a medium which is not itselfincompatible with lubrication, and therefore hydrocarbons are nowgenerally favored for this Purpose. A great variety of hydrocarbons havebeen proposed, including members of the aliphatic, or parafllnic andolefinic group, the aromatic or carbon ring group, and the alicyclic ornaphthenic group. These hydrocarbons are not, however, all equallysuitable for the purpose.

Some are diflicult to chlorinate or incapable of accepting more than asmall proportion of chlorine. Others when .chlori n.ate d are notsufliciently stable for the purposes intended. Still others aretoostable, holding the chlorine so 35 firmly that it cannot actefiectively. Some are open to" the further serious disadvantage thattheir chlorinated derivatives are of a very limited solubility inlubricating oils.

I have now discovered that certain new syn- 33 thetic petroleumproducts, to be hereinafter described, which do not fall clearly withinany of the above mentioned categories, possess unique properties asmediums for introduction of halogens-into lubricating oil. For thispurpose these 5 products seem to combine most of the desirablecharacteristics of all the hitherto known hydrocarbons. I refer to thehydrogenation products of petroleum, now supplied commercially for useas solvents under the trade name "Solvesso.

10 These petroleum hydrogenation products are made by subjecting lightpetroleum fractions to molecule-splitting conditions, such as pressures.

of the order of 3,000 lbs. or higher and temperatures of 300 C. or more,in the presence of hy- 3 drogen. A sulphur-resistant hydrogenationcatalyst may also be employed. The process is so controlled that,notwithstanding the presence of hydrogen, the resulting product ishydrogen-unsaturated.

50, The exact nature of the hydrogenation prod- Distillation 10 Sp. gr.,ml? 0. range, Example No.

mun Mean Final Initial Final 15 1 0.1561 0184 0.8250 as 145 0.857 0.8744136 189 0.897 0.9192 187 218 cm 0.95m 214 281 Referring to the drawing:20

This is a graphic comparison, upon the bases of specific gravitiesplotted against boiling points, of a large number of known hydrocarbons,with the petroleum hydrogenation products which I chlorlnate and use inthe lubricant of my invention. A At the extreme left of the sheet.curves 1 and 2 are plotted for the p'araflnes and oleiines respectively.It will be seen that these form very deflnite, smooth curves, which tendto go to infinity, with a gravity of about 0.78 as an asymptote in bothcases. Below these, curve I is similarly plotted for the naphthenes,cyclo-butane to cyclooctane. It will be seen at a glance that this alsois a definite, smooth curve, entirely distinct from the foregoing andhaving different characteristics in that, although it curves upward, ithas no asymptote. Below this is curve 0, similarly drawn forcyclo-pentene and cyclo-hexene. Curve 5 is plotted for benzene,naphthalene and anthracene, which are aromatic hydrocarbons of one, twoand three benzene rings respectively. This curve is very far fromcoinciding with any of the previous curves, but in common with them hasan upward curving tendency. Curve 6 is plotted for benzene, toluene andmlene, which are substituted benzenes differing in that toluene hasattached to it one methyl group and xylene two. This curve slopes in thereverse direction,

1. e., boiling point decreases instead of increasing 5o with gravity asin the previous cases. Diphenyl,

indene and retene form isolated points, having no near relatives.

Upon the same sheet the initial and final boiling points of the fourtypical petroleum hydrogenation products, above referred to'have beenplotted against their corresponding specific gravities as indicated atH, l2; l3, l4; l5, l6 and ill, i8 respectively. The two points soplotted for each product are joined by a dotted line. These dotted linesare designated as product I, product 2", "product 3 and product 4.Although these hydrogenation products are mixtures, the fractions forwhich the points are plotted, representing as they do the first and last0.5 percent of each product respectively, have fairly sharp boilingpoints and therefore tend toward chemical individuals.

These points lie in a zone which is overlapped by the curve drawn forthe naphthenes, cyclo butane to cyclo-octane. However, this curve tendsupward and its final portion nitely away from this zone.

None of these points fall upon this or any other of the curves plottedfor. the known hydrocarbons. not identifiable as members of any wellknown groups of hydrocarbons; and since the terminal fractions are notreadily classifiable, it is a fair presumption that some at least of theintermediate fractions are likewise unfamiliar compounds.

Moreover, these are not random mixtures. They are mixtures ofhydrocarbons formed simultaneously under identical conditions and hencepresumably closely related. They may be homologus. The resulting producttherefore might be expected to show unique physical and chemicalcharacteristics, and such is the case.

This is borne out by the following facts:

These petroleum hydrogenation products sulphonate freely. Sincesaturated hydrocarbons do not sulphonate this shows that to a largeextent these products are more or less hydrogenunsaturated. Moreover,this is also proven by the fact that they can be made to take up one tofive percent of additional hydrogen. Since the paramns and naphthenesare fully saturated compounds, the evidence of specific gravity andboiling point that these products are not paraflins or naphthenes isthus definitely confirmed. These hydrogenation products chlorinatefreely in light or darkness without the use of a catalyst and withoutfoaming, whereas certain aliphatic hydrocarbons, such as petrolatum,foam sobadly during chlorination that the operation becomes one of greatdifficulty. Although non-volatile, they readily take up chlorine to achlorine content of 60 percent or more by weight, without the use of asolvent to keep them in fluid condition during the process. In thisrespect they resemble the parafllns more than the carbonring compounds,which, unless they are chlorinated with a catalyst, produce unstableaddition compounds. These products differ from the parafllns, however,in that paraillns, the chains of which are long enough to benon-volatile, become so viscous when they have taken up chlorine-to acontent of 40 to 45 percent by weight that, unless they are dissolved ina solvent, the chlorination cannot be further continued. Duringchlorination of these products HCl is given off copiously, showing thatthe reaction is largely a substitution. 'W'hen freedfrom this HCl theyremain. substantially neutrahduring prolonged points defi- Thereforethese terminals fractions are actinic light, whereas chlorinatedaliphatic hy-- drocarbons, although stable in darkness, tend to give of!HCl when exposed to light.

These petroleum hydrogenation products when chlorinated are yellowishbrown, viscous, oily liquids, of a lighter .color, however, thanthechlorinated parafl'ins containing a comparable percentage of chlorine.They have no definite solidifying point, but upon cooling become moreand more viscous until finally they practically cease to flow; but theydo not become true solids at temperatures attainable by ordinary means.They do not become waxy and never contain more crystals than could beaccounted for by traces of impurities. In these respects again theyresemble the chlorinated paraillns and are.

in sharp contrast with the chlorinated carbonring compounds. Theselatter, in general, are characterized by sharp melting points. Atordinary temperatures they are generally either nonviscous, non-oilyliquids or waxy crystalline solids. This is especially true of thechlorinated benzenes and substituted benzenes. When chilled, with orwithout seeding, they can always be made to yield crystals, withliberation of the latent heat of the liquid. The diphenyls, in somegrades, are viscous, but they are sticky or syrupy rather than oily, andtend to cause a notable increase in friction.

These chlorinated petroleum hydrogenation products containing 60 percentchlorine or over are miscible at room temperature and higher in allproportions with lubricating oils. In this respect again they are likethe. chlorinated paraflinic hydrocarbons containing 30 to 45 percentchlorine and in sharp contrast with the chlorinated carbon-ring carbons,some of which are of very limited solubility in oils. Thus tetrachlorand hexachior benzene, containing respectively 65.7 and 74.6 percent ofchlorine, have a limit of solubility in oils of only about 2 percent.Chlornaphthalene and chlor-diphenyl, containing 56 and 68 percent ofchlorine, have limits of solubility in oils of 9 and 7 percentrespectively. Hexachlor-ethane, which contains 90 percent chorine. has asolubility in oils of about 9 percent.

These hydrogenation products may be chlorinatedat temperatures up to 1900., as compared with a limit of 130 Cfin the case of paraiilns. This, ofcourse, means that they are stable at a correspondingly highertemperature.

The fact that the chlorination of these hydrohave substantially the samelimits of chlorine content as the corresponding parafllns and the samegravity and decomposition temperature when chlorinated, in both of whichrespects they are quite difierent from any chlorinated carbonringcompounds.

To recapitulate, these petroleum hydrogenation products diifer from theparafins in that (a) They are largely unsaturated compounds,

whereas pa'rafllns are fully saturated.

(b) Their gravities for given boiling points are much higher.

(0) They readily take up chlorine to a chlorine content of 60 percent ormore by weight withstorage at ordinary temperatures, even under outbecomingso viscous as to require the use ofa solvent, whereas thenon-volatile paramns take u chlorine to a content of not more than 45percent under similar circumstances.

(d) These petroleum hydrogenation products may be chlorinated at 190 C.as compared with a limit of C. for the parafllns.

These hydrogenation products differ from the olefines in that (a) Theychlorinate largely by substitution.

(b) Their gravities are much higher for a. given boiling point.

(0) They take up more chlorine than chlorinated olefines, as indicatedunder the above comparison for paraffins.

These hydrogenation products differentiate from naphthenes in that (a)They are largely unsaturated compounds, whereas naphthenes are fullysaturated.

(b) They have a higher range of both gravity and boiling point.

These hydrogenation products differ from all well known carbon-ringcompounds in that (a) Their gravities and boiling points do notcorrespond to those of any known ring compounds.

(b) They chlorinate freely in the light or dark, without a catalyst, andwithout producing the unstable addition compounds obtained if knowncarbon-ring compounds are chlorinated under similar conditions.

(c) The chlorinated hydrogenation products are miscible with lubricatingoils at room temperature in all proportions, whereas the chlorinatedcarbon-ring compounds have upper limits of solubility in such oils offrom 2 to 9 percent.

(11) The chlorinated hydrogenation products are viscous, oily liquids atordinary temperatures, having no definite solidifying point, and neverbecoming true solids, whereas the chlorinated carbon-ring compounds passsharply from nonoily liquids to waxy, crystalline solids, with.liberation of the latent heat of the liquid.

In short, these hydrogen-unsaturated petroleum hydrogenation productsare probably hitherto unknown members or mixtures of the almostinfinitely diversified family of hydrocarbons.

These petroleum hydrogenation products, especially those in the lowerboiling ranges, when chlorinated to less than 50 percent chlorine, havean extremely unpleasant odor and irritant effect upon the skin. This maybe due to sulphur and nitrogen derivatives. 1'. have discovered,however, that when the chlorination is carried beyond 50 percent thisodor is destroyed and the irritant effect ceases.

These petroleum hydrogenation products therefore combine the mostdesirable properties of the aliphatic, alicyclic and carbon-ringhydrocarbons heretofore known, namely ease of chlorination to a highchlorine content, resulting in a sparklingly clear product, of lightcolor and unlimited solubility in oils which will not cause turbidity inthe oil and of good stability under heat. Moreover, when used inlubricants they have exceptional merit as film-strengthening agents.This is shown by the following tests:

Example of about lbs. upon the gauge of this machine. To this oil wasadded in various proportions chlorinated Solvesso boiling beforechlorination between 136 C. and 189 C., and

containing various percentages of chlorine. The

These comparative tests show that the addition of 1.5 to 1.8 percent ofchlorine in combination with these petroleum hydrogenation productsincreased the film strengthof the base oil from 140 lbs. upon the gaugeso that it was able to withstand the full limit of the machine of 600lbs. upon the guage without failure. These results are distinctlysuperior to those obtainable with the well known film strengtheningagents, such as chlorinated parafilns, chlorinated naphthalene, etc.,none of which consistently carry a load of much over 400 lbs. upon thegauge of the Floyd testing machine under the conditions of the abovetests.

Upon the drawing the initial and final boiling points of the first andfourth products have been plotted against their means specificgravities, as indicated at I, 8, 9 and 10. The initial boiling pointsand final boiling points of the two products respectively have beenjoined by dotted lines, which, with the two limiting gravities, form aquadrilateral enclosing an area within which the four products arelargely comprised. This area graphically defines by their gravities andboiling points substantially all the petroleum hydrogenation productscoming within the scope of my invention.

Point 1 of this quadrilateral appears to fall upon curve 3, but this hasno significance as point I is not drawn for a chemical individual.

Furthermore, it represents an unsaturated compound which could not be anaphthene. Points H and I8 fall outside the quadrilateral. This againhas no significance as their points represent the fractions that arevery nearly chemical individuals. Thus, point l8 represents the boilingpoint of the final fraction of product No. 4, plotted against its actualspecific gravity, whereas point 9 represents the boiling point of thesame fraction plotted against the mean gravity of the product as awhole.

In the following claims the expression relatively stable means more heatstable than the hitherto known oil-miscible addition agents forlubricants.

I claim as my invention: I

1. A lubricant composition of relatively high film strength comprising amajor proportion of a mineral lubricating oil and a minor propor tion ofan oily, liquid, relatively stable, substantially neutral andnon-volatile chlorination product, miscible in all proportions atordinary temperatures with said oil and containing not less than 45 percent of largely substituted chlorine, such as would be produced bychlorinating a hydrogen unsaturated petroleum hydrogenation ,producthaving a gravity above 0.78 and boiling between 89 C. and 281 C., suchas would be produced by subjecting a light petroleum fraction tomolecule-splitting conditions of temperature and pressure in presence ofhydrogen.

2. A lubricant composition of relatively high film-strength comprising amajor proportion of a mineral lubricating oil and a minor proportion ofan oily, liquid, relatively stable, substantially neutral andnon-volatile chlorination product, miscible in all proportions atordinary temperatures with said oil and containing not less than 45 percent of largely substituted chlorine, such as would be produced bychlorinating a. sulphonatable hydrocarbon having a gravity above 0.78and boiling between 89 C. and 281 C., such as would be produced bysubjecting a light petroleum fraction to molecule-splitting conditionsof temperature and pressure in presence of hydrogen.

3. A lubricant composition of relatively high film strength comprising amajor proportion of a mineral lubricating oil and a minor proportion ofan oily, liquid, relatively stable, substantially neutral andnon-volatile chlorination product, miscible in all proportions atordinary temperatures with said oil and containing not less than 45 percent of largely substituted chlorine, such as would be produced bychlorinating a hydrocarbon capable of taking up 1 to 5 per cent of itsweight of hydrogen having a gravity above 0.78 and boiling between 89 C.and 281 C., such as would be produced by subjecting a light petroleumfraction to molecule-splitting conditions of temperature and pressure inpresence of hydrogen.

4. A lubricant composition of relatively high film strength comprising amajor proportion of a mineral lubricating oil and a minor proportion ofan oily, liquid, relatively stable, substantially neutral andnon-volatile chlorination product, miscible in all proportions atordinary temperatures with said oil and containing not less than 45 percent of largely substituted chlorine, such as would be produced bychlorinating a hydrogen-unsaturated petroleum hydrogenation producthaving a gravity of substantially 0.855 and boiling between 136 C. and189 C., such as would be produced by subjecting a light petrole umfraction to molecule-splitting conditions of temperature and pressure inpresence of hydrogen.

5. A lubricant composition of relatively high film strength comprising amajor proportion of a mineral lubricating oil and a minor proportion ofan oily, liquid, relatively stable, substantially neutral andnon-volatile chlorination product, miscible in all proportions atordinary temperatures with said oil and containing not less than 45 percent of largely substituted chlorine, such as would be produced bychlorinating a hydrogen-unsaturated petroleum hydrogenation producthaving a gravity of substantially 0.987 and boiling between 187 C. and218 C., such as would be produced by subjecting a light petroleumfraction to molecule-splitting conditions of temperature and pressure inpresence of hydrogen.

6. A lubricant composition of relatively high film strength comprising amajor proportion of a mineral lubricating oil and a minor proportion ofan oily, liquid, relatively stable, substantially neutral andnon-volatile chlorination product, miscible in all proportions atordinary temperatures with said oil and containing not less than 45 percent of largely substituted chlorine, such as would be produced bychlorinating a hydrogen-unsaturated petroleum hydrogenation producthaving a gravity of substantially 0.937 and boiling between 214 C. and281 C., such as drogen.

7. A lubricant composition of relatively high.

film strength comprising a major proportion of a mineral lubricating oiland a minor proportion of an oily, liquid, relatively stable,substantially neutral and non-volatile chlorination product, miscible inall proportions at ordinary temperatures with said oil and containingnot less than 45 per cent of largely substituted chlorine, such as wouldbe produced by chlorinating a hydrogen-unsaturated petroleumhydrogenation product having a boiling range which when plotted againstthe gravity of said product falls within the quadrilateral formed bylines joining the four points plotted respectively for a gravity of0.784 against boiling points of 89 C. and 145 C. and a gravity of 0.937against boiling points of 214 C. and 281 C., such as would be producedby subjecting a light petroleum fraction to molecule-splittingconditions of temperature and pressure in presence of hydrogen.

8. A lubricant composition of relatively high film strength comprising amajor proportion of a mineral lubricating oil and a minor proportion ofan oily, liquid, relatively stable, non-irritating, substantiallyneutral and non-volatile chlorination product, miscible in allproportions at ordinary temperatures with said oil, such as would beproduced by chlorinating to not less than 50 per cent of largelysubstituted chlorine a hydrogen-unsaturated petroleum hydrogenationproduct having a gravity above 0.78 and boiling between 89 C. and 281C., such as would be produced by subjecting a light petroleum fractionto molecule-splitting conditions of temperature and pressure in presenceof hydrogen.

9. A lubricant composition of relatively high film-strength comprising amajor proportion of a mineral lubricating oil and a minor propor-' tionof an oily, liquid, relatively stable, substantially neutral andnon-volatile chlorination product, miscible in all proportions atordinary temperatures with said oil, such as would be produced bychlorinating at a temperature of 130 C. to 190 C., regardless of lightand in the absence of any catalyst a hydrogen-unsaturated petroleumhydrogenation product, such as would be produced by subjecting a lightpetroleum fraction to molecule-splitting conditions of temperature andpressure in presence of hydrogen.

10. The process for production of a lubricant composition of relativelyhigh film strength comprising passing chlorine into ahydrogen-unsaturated petroleum hydrogenation product having a gravityabove 0.78 and boiling between 89 C. and 281 C., such as would beproduced by subjecting a light petroleum fraction to moleculesplittingconditions of temperature and pressure in presence of hydrogen, at atemperature between 130 C. and 190 C., regardless of light WILLIAM J.MARSH.

